Interesting points you make. But what if we are at war, and at war with people who don’t observe the civilized standards you cite? To say that American servicemen committed murder in World War II ignores the fact that legally we were at war.
I believe that the vast majority of American servicemen did not commit murder in WWII.
My argument is only against the targeting of entire cities together with their populations. That is, the indiscriminate killing of civilians. That is murder, and most American fighting men emphatically did not do this.